Module 2: The Central Nervous System

Introduction to the Human Brain
The central nervous system (CNS) is central in both location and function.

The human central nervous system (CNS).

The fully formed CNS can be considered in two major subdivisions:

the brain
the spinal cord

The human brain has three major subdivisions:

brainstem
cerebellum
cerebrum

The Brainstem
The brainstem is the core of the brain.

We consider it in three parts--the hindbrainstem, the midbrainstem, and the forebrainstem.

In general, the brainstem is made up of many nuclei and fiber tracts.

It is a primary coordinating center of the human nervous system.

The Cerebellum
Over the hindbrainstem is the cerebellum.

The cerebellum is connected to both the midbrainstem and the hindbrainstem.

The cerebellum is the primary coordinating center for muscle actions.

Here, patterns of movements are properly integrated.

Thus, information is sent to the appropriate muscles in the appropriate sequences.

Also, the cerebellum is very much involved in the postural equilibrium of the body.

The Cerebrum
The two cerebral hemispheres are attached to the forebrainstem.

Together, these two hemispheres make up the cerebrum.

Among related species, the cerebrum is the newest development of the brain.